How are tornadoes named? How is it graded?

A tornado occurred in Kaiyuan City, Liaoning Province, killing 6 people and injuring 190 people. So how strong is it? The tornado has not yet been graded, and the authoritative investigation report needs to wait for grading. At present, China generally adopts the internationally recognized EF grade to determine the tornado grade. It is understood that EF grade belongs to the professional technical manual used by tornado classification in the United States, not an informal industry or national standard. According to the regulations of the Policy and Regulation Department of China Meteorological Bureau, the official industry standards based on the characteristics of tornado disasters in China will be implemented.

According to the Liaoning Meteorological Bureau, strong convective weather such as tornado, hail and short-term heavy precipitation occurred in Tieling, Liaoning. Weather radar shows that the strong echo entered Jingouzi Town in the northwest of kaiyuan city from Changtu County, Tieling, and moved to the southeast near kaiyuan city. The National Meteorological Observatory of Kaiyuan City 17:25 to 37 observed a tornado in Kaiyuan City. The measured maximum instantaneous wind speed is 23.0m/s (Grade 9).

According to Xinhua News Agency, the tornado has killed 6 people and injured 190 people. So how strong is it? The tornado is so small that the weather station can't directly observe it. Monitoring and forecasting are difficult. The intensity of tornado needs authoritative investigation report to evaluate.

At present, EF grade is commonly used to determine tornado grade in China. However, the EF level belongs to the professional technical manual used in tornado class, USA, and is not an informal industry or national standard. In order to better evaluate the intensity of tornadoes in China, China has formulated a formal industry standard that conforms to the characteristics of tornadoes in China and will be implemented soon.

It is reported that China meteorological industry standard "Tornado Intensity Grade" QX/T 478-20 19 will be implemented. This standard was drafted by China Institute of Meteorological Science and National Meteorological Center according to the EF grade of the United States, combined with the characteristics of tornado disasters in China, and based on the principles of standardization, practicality and operability.

On the basis of determining the occurrence of tornadoes, the intensity of tornadoes in China is divided into four grades with the maximum gust wind speed near the ground as the index. Compared with the six EF0-EF5 grades in the United States, the standard divides tornadoes into four grades. Among them, the first tornado corresponds to EF0 and below, the second tornado corresponds to EF 1, the third tornado corresponds to EF2 and EF3, and the fourth tornado corresponds to EF4 and EF5. This is mainly because, according to the actual experience of tornado investigation in China, it is difficult to divide the boundary between EF2 and EF3 in practical application, so they are merged. Moreover, the EF5 tornado hardly appeared in China, and EF4 was very rare, so it was merged.

1 level: gust wind speed ≤ 38m/s (13 and below), tornado intensity is weak, and the disaster degree is light. The doors and windows of the building were slightly damaged and the roof was slightly damaged. Telephone poles, street lamp poles and other telephone poles are slightly damaged. Branches were broken and tiny trunks were uprooted.

Level 2: 38m/s

Level 3: 49 m/s

Level 4: gust >; 74 meters per second (17 or above), the tornado intensity is super strong and the disaster degree is extremely high. The top floor of the building was completely destroyed and the house was razed to the ground. The tower is severely deformed. The trunk is severely deformed.